<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .content {
      background-color: #f00;
      color: white;
      /* width/height不生效 */
      width: 100px;
      height: 100px;
      /* 内边距  特殊:上下被撑起,但是不占空间 */
      /* padding: 50px; */
      /* 边框 特殊:上下被撑起,但是不占空间 */
      /* border: 50px solid orange; */
      /* 外边距 特殊:上下的margin不生效 */
      margin: 50px;
    }
  </style>
</head>

<body>
  <span class="content">我是span的内容</span>
  aaa
  <div>bbb</div>
</body>

</html>